rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

DM1_1980_I140174

Cross section for $e^+e^-\to\pi^+\pi^-\pi^0$ at energies between 0.75 and 1.1 GeV.
Experiment: DM1 (ACO)
Inspire ID: 140174
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Nucl.Phys. B172 (1980) 13-24, 1980
Beams: e+ e-
Beam energies: ANY
Run details:
  • e+e- to hadrons

Measurement of the cross section for $e^+e^-\to\pi^+\pi^-\pi^0$ at energies between 0.75 and 1.1 GeV.

Source code: DM1_1980_I140174.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4#include "Rivet/Projections/UnstableParticles.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief Add a short analysis description here
10  class DM1_1980_I140174 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(DM1_1980_I140174);
15
16
17    /// @name Analysis methods
18    //@{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22      // Initialise and register projections
23      declare(FinalState(), "FS");
24      declare(UnstableParticles(), "UFS");
25      book(_n3pi, "TMP/3pi");
26    }
27
28
29    /// Perform the per-event analysis
30    void analyze(const Event& event) {
31      const FinalState& fs = apply<FinalState>(event, "FS");
32      
33      map<long,int> nCount;
34      int ntotal(0);
35      for (const Particle& p : fs.particles()) {
36	nCount[p.pid()] += 1;
37	++ntotal;
38      }
39      if(ntotal==3 && nCount[211] == 1 && nCount[-211] == 1 && nCount[111] == 1)
40	_n3pi->fill();
41    }
42
43
44    /// Normalise histograms etc., after the run
45    void finalize() {
46      double sigma = _n3pi->val();
47      double error = _n3pi->err();
48      sigma *= crossSection()/ sumOfWeights() /nanobarn;
49      error *= crossSection()/ sumOfWeights() /nanobarn; 
50      Scatter2D temphisto(refData(1, 1, 1));
51      Scatter2DPtr mult;
52      book(mult, 1, 1, 1);
53      for (size_t b = 0; b < temphisto.numPoints(); b++) {
54	const double x  = temphisto.point(b).x();
55	pair<double,double> ex = temphisto.point(b).xErrs();
56	pair<double,double> ex2 = ex;
57	if(ex2.first ==0.) ex2. first=0.0001;
58	if(ex2.second==0.) ex2.second=0.0001;
59	if (inRange(sqrtS()/MeV, x-ex2.first, x+ex2.second)) {
60	  mult->addPoint(x, sigma, ex, make_pair(error,error));
61	}
62	else {
63	  mult->addPoint(x, 0., ex, make_pair(0.,.0));
64	}
65      }
66    }
67
68    //@}
69
70
71    /// @name Histograms
72    //@{
73    CounterPtr _n3pi;
74    //@}
75
76
77  };
78
79
80  // The hook for the plugin system
81  RIVET_DECLARE_PLUGIN(DM1_1980_I140174);
82
83
84}